Outside of the perspective of battles, the skill works as you expect. It creates brainwaves that travel and get absorbed by a target's brain, relaxing and steer it almost to the point of making the mind go blank and blind, hypnotizing it and be susceptible to suggestion. To know if the process worked, is if the target doesn't respond to other voices until the user says to do so and when the target's pupils change to squared swirls (fitting with the PSI effect aesthetic).
Has many possibilities including brainwashing, mind and body control, memory manipulation (loss or recovery), etc.
Despite that potential, Chris isn't very sure of why he has this kind of power, struggling himself with the morals of it.
In fact, when he awakened this power, he refused to use it ever especially considering the situation what was going on, relating of how the enemy was the using this kind of power currently and how was affecting his dear beloved ones causing a lot of hurt including him (if you followed me on Miiverse you may recognize what I'm talking about).
Later on, because of the encouragement of his friends including Greninja and Dakota via an important moral, they convinced him to accept this power as part of his own, for the sake of not letting the boy accumulate a ton of energy that could damage his body like when a person accumulates of an emotion without letting out causing hurt, but to also for Chris learn that it depends of himself how he wants or sees any power he possesses and what results it would give, giving him support to many ideas of how he could use this skill while still following his beliefs and once in a while find good and fun with it with no harm.